Acarette du Biscay, a French traveler, described it thus in 1658: ...[the city] has a small earthen fort overlooking the river encircled by a moat and mounts ten iron cannons being the largest caliber of twelve.

Originally the fortress had been raised for the defense of the city against possible incursions by pirates, was also the residence of the authorities of Buenos Aires.

[6] Towards the middle of the 18th century, the Fort of Buenos Aires continued with the renovations, carried out by the Spanish engineer of British descent, Don Juan Bartolomé Howell.

[8] During the British invasions of the River Plate, the Fort of Buenos Aires, was occupied by William Beresford, who resided in the fortification until surrendering to Santiago de Liniers.

[9] In 1810 the Fort of Buenos Aires, was used as the official residence of Cornelio Saavedra, president of the Primera Junta of Government.